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Author Notes:

Correspondence: rsingh@emory.edu

TDD was responsible for grant and protocol writing, adaptation of QOLQ for adult study population, distribution and collection of questionnaires, data entry, data management and analysis, statistical interpretation, and writing all parts of the manuscript including tables and graphs.

UR made significant contributions in reviewing the article, advising analytical and statistical approaches as well as appropriate data management techniques, in recommending large scale revisions, and for providing additional project guidance and support. JAK provided crucial guidance regarding data collection, management, and analysis; and reviewed data results, provided feedback on statistical approaches, and assisted with reviewing and editing of the article drafts.

RHS was the study Principle Investigator, provided management and supervision of grant writing, protocol development, patient dietetic management, data management, staff research activities, and data reporting; contributed to review and revising all manuscript drafts. All authors read and approved the final manuscript.

Special appreciation to the patients who participated in the study. Thanks to Mary Jane Kennedy (project coordinator), Sarah Travis (research dietitian), Paul Fernhoff (MD), Muhammed Ali (MD) and additional faculty and staff within the Emory Genetics Clinic and Emory Genetics Laboratory.

Thanks also to Phyllis Acosta, Kathryn Coakley, Sarah Yi and Meghan Quirk for their guidance and support, and to Emory statistician George Cotsonis for his guidance on statistical methods.

Independent Investigator sponsored trial with partial funding provided by BioMarin Pharmaceutical Inc.


Research Funding:

Supported in part by PHS Grant UL1 RR025008 from the Clinical and Translational Science Award program, National Institutes of Health, National Center for Research Resources


  • Phenylketonuria
  • PKU
  • Quality of life
  • Sapropterin
  • Tetrahydrobiopterin
  • BH4
  • Medical diet

Longitudinal quality of life analysis in a phenylketonuria cohort provided sapropterin dihydrochloride


Journal Title:

Health and Quality of Life Outcomes


Volume 11


, Pages 218-218

Type of Work:

Article | Final Publisher PDF


Background Sapropterin dihydrochloride effectively lowers plasma phenylalanine (Phe) for at least a third of phenylketonuria (PKU) patients, with potential for increased dietary Phe tolerance and decreased medical food requirement. Objective To investigate long-term quality of life (QOL) in patients with phenylketonuria (PKU) who took sapropterin (BH4, Kuvan®) for up to one year. Methods 37 PKU patients, ages 10–49 years, were asked to complete a PKU-specific self-report QOL questionnaire (QOLQ) at baseline, 1, 4, 8, and 12 months. Questions were scored on a 5-point Likert scale under 5 sub-sections measuring Impact, Worries, Satisfaction, Support, and General wellbeing in relation to PKU. Responders with a plasma Phe decrease ≥ 15% after 1 month on sapropterin remained on the drug; Nonresponders ceased sapropterin after the trial month. Responders able to relax medical diet and maintain plasma Phe control were classified as Definitive; Responders unable to relax medical diet were classified as Provisional. All patients were routinely monitored by a registered dietitian. Data was analyzed in SPSS 19.0 using regression techniques. Results Of 17 Responders, 11 could maintain adequate Phe control on a less restrictive diet. One year mean Impact sub-score trends improved significantly for all sapropterin response groups, with greatest improvement among Definitive Responders (p < 0.0001). Satisfaction sub-scores also improved for Definitive Responders (p = 0.001). Trends for Total QOL score improved significantly over time for both Definitive (p = 0.001) and Provisional Responders (p = 0.028). Improvements in Definitive Responder scores were associated with increased Phe tolerance (Impact: p < 0.0001, Satisfaction: p = 0.022, Total QOL: p = 0.005) and MF adjustment (Satisfaction: p = 0.014, Total QOL: p = 0.026). Other sub-section scores remained steady, unaffected by sapropterin response or diet modification. Conclusion Increased Phe tolerance and reduced MF requirement in sapropterin Definitive Responders improves QOL perception across one year, specifically for life impact and satisfaction. Keywords: Phenylketonuria, PKU, Quality of life, Sapropterin, Tetrahydrobiopterin, BH4, Medical diet

Copyright information:

© 2013 Douglas et al

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